| 摘要 |
<p>A device at a heating or cooling unit such as, for example, a heat pump where the energy carrier is a substance, the volume of which varies substantially with the temperature, for example freon. At such a unit, which comprises condenser (1,2), evaporator (1,2) and compressor (3),and where the compressor is driven by an electric motor (18), according to the invention a tank (21) is provided to contain said substance (22) and is connected to the suction side (19) and, respectively, pressure side (20) of the compressor(3) by two respective conduits (23,24), each of which is provided with an electrically controlled valve (25,26) for closing and, respectively, opening the conduit in question. A control circuit (27) is provided to sense the load of the motor (18) and in response to said load to actuate said valves (25,26) so as thereby to control the filling and draining of said substance (22) to and, respectively, from the system, from and, respectively, to said tank (21) in order to have in the system such an amount of said substance that a predetermined pressure is maintained in the system in order thereby to obtain a good efficiency degree of the unit at different temperatures of the same.</p> |
